The British Medical Journal released two reviews/meta-analyses and a guest editorial on vitamin D supplementation. The pieces, "Vitamin D and risk of cause specific death: systematic review and meta-analysis of observational cohort and randomized intervention studies" (BMJ. 2014 Apr 1;348:g1903); "Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational studies and randomized trials" (BMJ. 2014 Apr 1;348:g2035); and "Vitamin D and chronic disease prevention" (BMJ. 2014 Apr 1;348:g2280) all discuss vitamin D and its effects on overall health and wellness.
"The body of scientific research demonstrating beneficial results for vitamin D has grown in recent years. We know that vitamin D is a critical conduit for multiple physiological bodily functions, as well as a tool for helping calcium absorption, which is essential to building strong bones," said Duffy MacKay, N.D., senior vice president, scientific and regulatory affair, Council for Responsible Nutrition.
The first review and meta-analysis, "Vitamin D and risk of cause specific death," focuses on the evidence from observational studies and concludes that supplementation with vitamin D3 significantly reduces overall mortality among older adults, though it recommends further investigation.
"Now, a new systematic review and meta-analysis finds vitamin D supplementation may also play a significant role in reducing the risk of mortality, particularly in older adults," MacKay said. "We agree with the study authors that further research should be done to identify an optimal dose and duration for this encouraging finding; but there is enough positive research currently to indicate that people should be supplementing with vitamin D for a variety of positive health outcomes."
The second review, "Vitamin D and multiple health outcomes," sought to evaluate the breadth, validity and presence of biases in the associations of vitamin D with diverse outcomes.
"Although the second umbrella review in this week’s issue, by Theodoratou et al., recognized ‘probable’ and ‘suggestive’but not ‘highly convincing of a clear role’associations for vitamin D and various conditions and diseases, it also indicated that further research is needed to draw firmer conclusions, " MacKay said. "There are very few things that provide clear cut scientific evidence when you’re talking about chronic disease, and if adding a simple vitamin D supplement might provide even probable benefits in this area, as one of a host of healthy habits, we should encourage that step."
The guest editorial, "Vitamin D and chronic disease prevention," looks at the two previously mentioned reviews and analyses, as well as others looking at vitamin D consumption and health benefits.
The editorial suggests a few things: observational data needs to be treated cautiously by healthcare professionals as existing disease and associated risk factor may cause low circulating 25-hydroxyvitamin D, rather than be a consequence of it; new trial data is needed, with focus on potential risks and benefits before widespread supplementation is considered; and that clinicians should avoid costly measurement of 25-hydroxyvitamin D in asymptomatic patients outside of bone disease-related conditions.
"BMJ’s editorial doesn’t mention anything about numerous common prescription medications that can interfere with the absorption, utilization and/or metabolism of vitamin D, including drugs such as prednisone, orlistat, cholesterol-lowering drugs, which millions take daily, phenobarbital and phenytoin, to name a few," said Alex Schauss, Ph.D., senior research director, natural and medicinal products research, AIBMR Life Sciences, Inc. and Natural Products Association ComPLI committee member.
The editorial also discussed a new trial underway, VITAL, which will assess whether any benefits of vitamin D3 vary by baseline 25-hydroxyvitamin D concentrations. The results are due in 2017.
"It is rather striking that the BMJ editorial, which was 'not externally peer reviewed,' and whose second author is a 'consultant for pharmaceutical companies for work related to lipid lowering drugs,' couldn’t wait until 2017 to learn of the outcome of a prospective 26,000 subject VITAL study currently underway, to determine the effect of vitamin D-3 supplementation on primary outcomes including cancer, coronary heart disease, and stroke," Schauss said.
The final conclusion of the editorial was better lifestyles in general and targeting established risk factors is the best way to improve health and prevent chronic disease.
"It is important for patients and their healthcare practitioners to work together to ensure they are getting the recommended amount of vitamin D, which is not easily obtainable through food alone, and may not be safely available through the sun, making vitamin D supplements a safe and beneficial alternative," MacKay said.